Who am I?

“Who are You?” said the Caterpillar. This was not an encouraging opening for a conversation. Alice replied, rather shyly, “I – I hardly know, Sir, just at present – at least I know who I was when I got up this morning, but I think I must have been changed several times since then." “What do you mean by that?” said the Caterpillar, sternly. “Explain yourself!” “I can’t explain myself, I’m afraid, Sir,” said Alice, “because I’m not myself, you see.” (Lewis Carroll: 1960)